Boiler fan runs but burner does not light, no error code displayed
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: Turn off gas and power before internal inspection. Only a qualified technician should work on ignition and gas systems.
Technician steps:
- Check ignition spark: Observe through the sight glass whether a strong spark is present during ignition attempts.
- Verify gas valve operation: Confirm that the gas valve receives an open signal and that gas pressure is present.
- Test flame sensor: Clean or replace the flame sensing electrode and check ionization current.
If the PCB fails to detect flame despite correct combustion, the PCB may require replacement.
Repair Difficulty
Required Part
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